The Green Pass costs about $800 for 14 days. The regular pass costs $590. Over $200 difference.
BUT, I just realised that other than the long distance between Osaka and Tokyo, other short distance do not offer green cars. So there is no call for a Green pass. The Osaka-Kobe-Kyoto-Nara routes are so short that a regular pass will do.
Also the Rail Pass does not allow travel on the fastest Shinkansen, the Nozomi.
Trip will also take just over 200 minutes (about 3.5 hours).
Without using the Nozomi Shinkansen, it would be about Y15,000 and it would be covered by the Green Rail Pass (no extra fare).
But the trip will take closer to 4 hours.